Java Program to Merge Two String Arrays

Introduction

Merging two string arrays is a common task in programming, especially when dealing with collections of data. This exercise helps you understand how to work with arrays and concatenate their elements into a single array in Java. This guide will walk you through writing a Java program that merges two string arrays into one.

Problem Statement

Create a Java program that:

• Defines two string arrays.
• Merges these two arrays into a single array.
• Displays the merged array.

Example:

• Input Arrays:

  String[] array1 = {"Apple", "Banana", "Cherry"};
  String[] array2 = {"Date", "Fig", "Grape"};
  

• Output:

  Merged array: ["Apple", "Banana", "Cherry", "Date", "Fig", "Grape"]
  

Solution Steps

1. Define Two String Arrays: Create two string arrays with predefined values.
2. Create a Merged Array: Initialize a new array that will hold the elements of both arrays.
3. Copy Elements to Merged Array: Use the System.arraycopy() method to copy elements from both arrays into the merged array.
4. Display the Merged Array: Print the merged array.

Java Program

// Java Program to Merge Two String Arrays
// Author: https://www.rameshfadatare.com/

import java.util.Arrays;

public class StringArrayMerger {
    public static void main(String[] args) {
        // Step 1: Define two string arrays
        String[] array1 = {"Apple", "Banana", "Cherry"};
        String[] array2 = {"Date", "Fig", "Grape"};
        
        // Step 2: Create a merged array
        String[] mergedArray = new String[array1.length + array2.length];
        
        // Step 3: Copy elements from both arrays to the merged array
        System.arraycopy(array1, 0, mergedArray, 0, array1.length);
        System.arraycopy(array2, 0, mergedArray, array1.length, array2.length);
        
        // Step 4: Display the merged array
        System.out.println("Merged array: " + Arrays.toString(mergedArray));
    }
}

Explanation

Step 1: Define Two String Arrays

• Two string arrays, array1 and array2, are initialized with predefined values.

Step 2: Create a Merged Array

• A new string array, mergedArray, is created with a size equal to the sum of the lengths of array1 and array2.

Step 3: Copy Elements to the Merged Array

• The System.arraycopy() method is used to copy the elements from array1 to the beginning of mergedArray.
• The same method is then used to copy the elements from array2 to the end of mergedArray, starting from the index after the last element of array1.

Step 4: Display the Merged Array

• The Arrays.toString() method is used to convert the merged array to a string for easy printing.

Output Example

Example:

Merged array: [Apple, Banana, Cherry, Date, Fig, Grape]

Conclusion

This Java program demonstrates how to merge two string arrays into a single array. It covers essential concepts such as array manipulation, using the System.arraycopy() method, and printing arrays, making it a useful exercise for beginners learning Java programming.